Intelligent bidirectional multifunctional carrier and integrated automation system for material distribution and transportation

ABSTRACT

An automation system for an in vitro diagnostics environment includes a plurality of intelligent carriers that include onboard processing and navigation capabilities. A central management controller can communicate wirelessly with the carriers to direct the carriers to carry a fluid sample to testing stations along a track within the automation system. The carriers control local motion and navigate decision points, such as forks in the track, to reach the appropriate testing station independently. The carriers can utilize landmarks and distance encoding to reach destinations accurately and quickly, including, for example, within less than the time for a single operation cycle of an automated clinical analyzer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional application Ser.No. 61/594,476 filed Feb. 3, 2012, which is incorporated herein byreference in its entirety.

TECHNOLOGY FIELD

The present invention relates in general to an automation system for usein a laboratory environment and, more particularly to systems andmethods for transporting patient samples for in vitro diagnostics in aclinical analyzer via active transport devices. Embodiments of thepresent invention are particularly well suited, but in no way limited,to independent carriers having an active direction and routingcapabilities and/or autonomous motive mechanisms.

BACKGROUND

In vitro diagnostics (IVD) allows labs to assist in the diagnosis ofdisease based on assays performed on patient fluid samples. IVD includesvarious types of analytical tests and assays related to patientdiagnosis and therapy that can be performed by analysis of a liquidsample taken from a patient's bodily fluids, or abscesses. These assaysare typically conducted with automated clinical chemistry analyzers(analyzers) onto which fluid containers, such as tubes or vialscontaining patient samples have been loaded. The analyzer extracts aliquid sample from the vial and combines the sample with variousreagents in special reaction cuvettes or tubes (referred to generally asreaction vessels). In some conventional systems, a modular approach isused for analyzers. A lab automation system can shuttle samples betweenone sample processing module (module) and another module. Modules mayinclude one or more stations, including sample handling stations andtesting stations (e.g., a unit that can specialize in certain types ofassays or can otherwise provide testing services to the largeranalyzer), which may include immunoassay (IA) and clinical chemistry(CC) stations. Some traditional IVD automation track systems comprisesystems that are designed to transport samples from one fullyindependent module to another standalone module. This allows differenttypes of tests to be specialized in two different stations or allows tworedundant stations to be linked to increase the volume of samplethroughput available. These lab automation systems, however, are oftenbottlenecks in multi-station analyzers. Relatively speaking, traditionallab automation systems lack large degrees of intelligence or autonomy toallow samples to independently move between stations.

In an exemplary prior art system, a friction track, much like a conveyorbelt, shuttles individual carrier mechanisms, sometimes called pucks, orracks of containers between different stations. Samples may be stored insample containers, such as test tubes that are placed into a puck by anoperator or robot arm for transport between stations in an analyzeralong the track. This friction track, however, can only move in onedirection at a time and any samples on the track will move in the samedirection at the same speed. When a sample needs to exit the frictiontrack, gating/switching can be used to move individual pucks intooffshoot paths. A drawback with this set up is that singulation must beused to control the direction of any given puck at each gate and switch.For example, if two pucks are near one another and only one puck shouldbe redirected into an offshoot path, it becomes difficult to control aswitch so that only one puck is moved into the offshoot path and ensurethat the proper puck is pulled from the friction track. This has createdthe need in many prior art systems to have pucks stop at a gate so thatindividual pucks can be released and switched one at a time at eachdecision point on a track.

Another way that singulation has been used in friction track-basedsystems is to stop the puck at a gate and allow a barcode reader to reada barcode on the sample tube. Because barcode readers are slow relativeto the amount of time needed to switch a puck between tracks, scanningintroduces hard singulations into the flow on a track and causes allnearby pucks to halt while a switching determination is made. After adetermination is made, singulation may be further used to ensure thatonly the scanned puck proceeds by using a physical blockage to preventthe puck behind the scanned puck from proceeding while the scanned puckis switched.

U.S. Pat. No. 6,202,829 shows an exemplary prior art friction tracksystem that includes actuated mechanical diversion gates that can beused to direct pucks off of the main track onto pullout tracks. Asexplained therein, the diversion process can require multiple mechanicalgates to singulate and separate individual pucks, stopping each puckmultiple times and allowing each puck to be rotated so that a barcodecan be read before a diversion decision is made. Such a system increaseslatency and virtually ensures that each time a diversion gate is addedto a friction track the gate adds another traffic bottleneck. Such asystem results in natural queuing at each diversion gate furtherincreasing the amount of time that each sample spends on the frictiontrack.

Hard singulation slows down the overall track and increases traffic jamswithin the track. This leads to the need for physical queues within thetrack. Much like traffic on a road, traffic on the track causes anaccumulation of slow-moving pucks because most of the time spent intransit during operation can be spent waiting through a line at asingulation point for switching by a gate. This leads to inefficiency intransit. Ultimately for a high volume analyzer, a substantial amount oftime for each sample is spent waiting in queues at the gates on thefriction track. This increases the latency experienced by each sample.Latency can be a problem for certain types of samples, such as wholeblood samples, which can begin to separate or coagulate if the samplesits in the sample tube for too long.

Another problem with long queues and traffic on the friction track isthe issue of handling STAT samples. A STAT sample is a sample that anoperator wishes to have moved to the front of the line so that resultsfor that sample can be returned quickly. For example, in a hospital withan emergency room, test results may be urgent for a patient awaitingtreatment. In prior art friction track systems with long queues, theentire queue often must be flushed to make way for the STAT sample. Thiscan undo several minutes worth of sorting of samples and can increasethe overall latency experienced by non-STAT samples.

SUMMARY

Embodiments of the present invention may address and overcome one ormore of the above shortcomings and drawbacks by providing devices andsystems for transporting samples using intelligent carriers that can bepartially or substantially autonomous. This technology is particularlywell-suited for, but by no means limited to, transport mechanisms in anautomation system for use in an in vitro diagnostics (IVD) environment.

Embodiments of the present invention are generally directed to anautomation system that can include a track, a plurality of carriers formoving fluid samples, and one or more central controllers that conveysrouting instructions to the carriers, such that the carriers cantransport fluid samples independently. Carriers can include one or moreprocessors and a communications system for interacting with the centralcontroller, and can be further configured to route samples viaindependent locomotion and routing to a destination testing station inan in vitro diagnostics system.

According to one embodiment of the invention, an automation systemincludes a track configured to provide one or more paths between aplurality of testing stations, a plurality of carriers, each includingan onboard processor configured to make local trajectory decisions, andone or more central controllers configured to assign destinations to theplurality of carriers and convey routing instructions to the pluralityof carriers, which includes an identification of at least one tracksection to traverse. These carriers are configured to hold one or morefluid samples and move the one or more fluid samples to one of theplurality of testing stations in response to receiving the routinginstructions.

According to another aspect of some embodiments, each carrier isconfigured to monitor and limit acceleration to a threshold that dependson the fluid sample being carried. According to another aspect of someembodiments, each carrier is configured to monitor and limit jerk to athreshold that depends on the fluid sample being carried. According toanother aspect of some embodiments, each carrier is configured toobserve landmarks in the track to determine its current location.According to yet another aspect, each carrier is configured to observelandmarks in the track to determine its current location relative to adecision point. According to still another aspect, the track includes aplurality of decision points that allow a carrier to be routed betweenmultiple sections within the track and each carrier is configured tomake a routing determination for each decision point it encounters.According to an additional aspect, each carrier is further configured tomake the routing determination without coming to a stop.

In another embodiment of the invention, a carrier for transporting fluidsamples in an in vitro diagnostics environment includes a processorconfigured to navigate the carrier between a plurality of points in thetrack and a communications system configured to receive a first set ofrouting instructions, including at least one destination testingstation. The processor is further configured to direct the carrier tothe at least one destination testing station autonomously upon receiptof the first set of routing instructions.

According to another aspect of some embodiments, the carrier includesone or more sensors configured to detect a collision condition with oneor more other carriers. According to another aspect of some embodiments,the processor is configured to monitor and limit acceleration to athreshold that depends on the fluid sample being carried. According toanother aspect, the processor is configured to monitor and limit jerk toa threshold that depends on the fluid sample being carried. Accordingyet another aspect, the carrier is configured to observe landmarks inthe track to determine its current location. According to still anotheraspect, the track includes a plurality of decision points that allow acarrier to be routed between multiple sections within the track and thecarrier is configured to make a routing determination for each decisionpoint it encounters. According to an additional aspect of someembodiments, the processor is further configured to make the routingdetermination without coming to a stop.

In a further embodiment of some embodiments, an automation system foruse in in vitro diagnostics includes a plurality of stations, includingat least one testing station, a track configured to provide one or morepaths between the plurality of stations, and a plurality of carriers.Each of the plurality of carriers is configured to carry one or morefluid containers and traverse the track between the plurality ofstations. The plurality of carriers move independently in accordancewith a predefined motion profile.

According to one aspect of some embodiments, each of the plurality ofcarriers can include an onboard processor. Each of the plurality ofcarriers may be configured to monitor and limit acceleration to athreshold that depends on a fluid sample being carried and/or monitorand limit jerk to a threshold that depends on a fluid sample beingcarried. According to another aspect of some embodiments, the track caninclude a plurality of decision points that allow each of the pluralityof carriers to be routed between multiple sections within the track andeach carrier can be configured to make a routing determination for eachdecision point it encounters. Each of the plurality of carriers may befurther configured to make routing determinations without coming to astop.

Additional features and advantages of the invention will be madeapparent from the following detailed description of illustrativeembodiments that proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of the present invention are bestunderstood from the following detailed description when read inconnection with the accompanying drawings. For the purpose ofillustrating the invention, there is shown in the drawings embodimentsthat are presently preferred, it being understood, however, that theinvention is not limited to the specific instrumentalities disclosed.Included in the drawings are the following Figures:

FIG. 1 is a top view of an exemplary clinical analyzer geometry that canbe improved by use of the automation system embodiments disclosed;

FIGS. 2A and 2B are diagrammatic views of track geometries that can beused with the automation system embodiments disclosed herein;

FIG. 3 is a diagrammatic view of an exemplary modular trackconfiguration that can be used with the embodiments disclosed herein;

FIG. 4A is a perspective view of an exemplary carrier that can be usedwith the embodiments disclosed herein;

FIG. 4B is a perspective view of an exemplary track configuration thatcan be used with the embodiments disclosed herein;

FIG. 4C is a top view of an exemplary automation system that can be usedwith the embodiments disclosed herein;

FIG. 5 is a system block diagram of the control systems includingonboard active carriers that can be used with certain embodimentsdisclosed herein;

FIG. 6 is a diagrammatic view of exemplary routes in an exemplary trackconfiguration that can be used for navigation of sample carriers incertain embodiments;

FIG. 7 is a flow diagram showing the operation of the navigation ofsample carriers in certain embodiments; and

FIG. 8 is an exemplary acceleration profile used by sample carriers incertain embodiments.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Terms and ConceptsAssociated with Some Embodiments

Analyzer:

Automated clinical analyzers (“analyzers”) include clinical chemistryanalyzers, automated immunoassay analyzers, or any other type of invitro diagnostics (IVD) testing analyzers. Generally, an analyzerperforms a series of automated IVD tests on a plurality of patientsamples. Patient samples may be loaded into an analyzer (manually or viaan automation system), which can then perform one or more immunoassays,chemistry tests, or other observable tests on each sample. The termanalyzer may refer to, but is not limited to, an analyzer that isconfigured as a modular analytical system. A modular analytical systemincludes an integrated and extendable system comprising any combinationsof a plurality of modules (which can include the same type of module ordifferent types of modules) interconnected in a linear or othergeometric configuration by an automation surface, such as an automationtrack. In some embodiments, the automation track may be configured as anintegral conveyance system on which independent carriers are used tomove patient samples and other types of material between the modules.Generally, at least one module in a modular analytical system is ananalyzer module. Modules may be specialized or made redundant to allowhigher throughput of analytical tasks on patient samples.

Analyzer Module:

An analyzer module is a module within a modular analyzer that isconfigured to perform IVD tests, such as immunoassays, chemistry tests,or other observable tests on patient samples. Typically, an analyzermodule extracts a liquid sample from a sample vessel and combines thesample with reagents in reaction cuvettes or tubes (referred togenerally as reaction vessels). Tests available in an analyzer modulemay include, but are not limited to, a subset of electrolyte, renal orliver function, metabolic, cardiac, mineral, blood disorder, drug,immunoassay, or other tests. In some systems, analyzer modules may bespecialized or made redundant to allow higher throughput. The functionsof an analyzer module may also be performed by standalone analyzers thatdo not utilize a modular approach.

Carrier:

A carrier is a transportation unit that can be used to move samplevessels (and, by extension, fluid samples) or other items in anautomation system. In some embodiments, carriers may be simple, liketraditional automation pucks (e.g., passive devices comprising a holderfor engaging a tube or item, a friction surface to allow an externalconveyor belt in the automation track to provide motive force, and aplurality of sides that allow the puck to be guided by walls or rails inthe automation track to allow the track to route a puck to itsdestination). In some embodiments, carriers may include activecomponents, such as processors, motion systems, guidance systems,sensors, and the like. In some embodiments, carriers can include onboardintelligence that allows carriers to be self-guided between points in anautomation system. In some embodiments, carriers can include onboardcomponents that provide motive forces while, in others, motive forcesmay be provided by an automation surface, such as a track. In someembodiments, carriers move along automation tracks that restrict motionto a single direction (e.g., fore and aft) between decision points.Carriers may be specialized to a given payload in an IVD environment,such as having a tube holder to engage and carry a sample tube, or mayinclude mounting surfaces suitable to carry different items around anautomation system. Carriers can be configured to include one or moreslots (e.g., a carrier may hold one or a plurality of sample vessels).

Central Controller or Processor:

A central controller/processor (which may sometimes be referred to as acentral scheduler) is a processor that is part of the automation system,separate from any processors onboard carriers. A central controller canfacilitate traffic direction, scheduling, and task management forcarriers. In some embodiments, a central controller can communicate withsubsystems in the automation system and wirelessly communicate withcarriers. This may also include sending trajectory or navigationalinformation or instructions to carriers and determining which carriersshould go where and when. In some embodiments, local processors may beresponsible for managing carriers on local track sections, such asmanaging local queues. These local processors may act as localequivalents to central controllers.

Decision Point:

Decision points are points on an automation track where differentnavigational or trajectory decisions may be made for different carriers.A common example includes a fork in a track. One carrier may proceedwithout turning, while another may slow down and turn. Decision pointsmay include stopping points at instruments, where some carriers maystop, while others may proceed. In some embodiments, deceleration zonesahead of turns may act as decision points, allowing carriers that willbe turning to slow down to limit lateral forces, while others mayproceed if not turning or if the motion profile for that carrier doesnot require slowing down. The decisions made at decision points can bemade by processors onboard carriers, processors local to the tracksection, a central processor, or any combination thereof, depending onthe embodiment.

Independent Carrier:

In some embodiments, carriers may be characterized as independentlycontrolled carriers. Independently controlled carriers are carriers withindependently controlled trajectories. In some embodiments, independentcarriers may be operating at the same time, on the same track, withcarriers carrying one or a plurality of combinations of payloads thatdiffer by size, weight, form factor, and/or content. The trajectories ofeach independently controlled carrier may be limited by a motion profilethat includes; maximum jerk, acceleration, direction, and/or speed forthe carrier while moving in the automation system. The motion profilecan limit or define the trajectory for each carrier independently. Insome embodiments, a motion profile can be different for differentsections of the automation system (e.g., in straight track sections vs.around curves to account for the added lateral forces while turning),for different carrier states (e.g., an empty carrier may have adifferent motion profile from a carrier transporting a sample or from acarrier transporting a reagent or other item), and/or for differentcarriers. In some embodiments, carriers can include onboard propulsioncomponents that allow individual carriers to independently operateresponsive to a motion profile or trajectory or destination instructionsintended for each separate carrier.

Intelligent Carrier/Semi-Autonomous Carriers:

In some embodiments, carriers may be characterized as intelligentcarriers. An intelligent carrier is a carrier with onboard circuits thatparticipates in motion, routing, or trajectory decisions. An intelligentcarrier can include digital processors that execute softwareinstructions to proceed along an automation surface responsive to theinstructions or onboard analog circuits that respond to motion input(e.g., line follower circuits). Instructions may include instructionscharacterizing motion profiles, traffic, or trajectory rules. Someintelligent carriers may also include onboard sensors to assist onboardprocessors to route the carrier or make decisions responsive to thecarrier's environment. Some intelligent carriers may include onboardcomponents, such as motors or magnets, which allow the carrier to moveresponsive to control of an onboard processor.

In Vitro Diagnostics (IVD):

In vitro diagnostics (IVD) are tests that can detect diseases,conditions, infections, metabolic markers, or quantify variousconstituents of bodily materials/fluids. These tests are performed inlaboratory, hospital, physician office, or other health professionalsettings, outside the body of a patient. IVD testing generally utilizesmedical devices intended to perform diagnoses from assays in a test tubeor other sample vessel or, more generally, in a controlled environmentoutside a living organism. WD includes testing and diagnosis of diseaseor quantifying various constituents of bodily materials/fluids based onassays performed on patient fluid samples. IVD includes various types ofanalytical tests and assays related to patient diagnosis and therapythat can be performed by analysis of a liquid sample taken from apatient's bodily fluids, or abscesses. These assays are typicallyconducted with analyzers into which tubes or vials containing patientsamples have been loaded. IVD can refer to any subset of the IVDfunctionality described herein.

Landmarks:

In embodiments where carriers include onboard sensors, optical or othermarks in track surfaces or locations viewable/sensible from tracksurfaces can act as landmarks. Landmarks can convey geographicinformation to carriers, such as a current location, upcoming stoppinglocation, decision point, turn, acceleration/deceleration points, andthe like.

Lab Automation System:

Lab automation systems include any systems that can automatically (e.g.,at the request of an operator or software) shuttle sample vessels orother items within a laboratory environment. With respect to analyzers,an automation system may automatically move vessels or other items to,from, amongst, or between stations in an analyzer. These stations mayinclude, but are not limited to, modular testing stations (e.g., a unitthat can specialize in certain types of assays or can otherwise providetesting services to the larger analyzer), sample handling stations,storage stations, or work cells.

Module:

A module performs specific task(s) or function(s) within a modularanalytical system. Examples of modules may include: a pre-analyticmodule, which prepares a sample for analytic testing, (e.g., a decappermodule, which removes a cap on top of a sample test tube); an analyzermodule, which extracts a portion of a sample and performs tests orassays; a post-analytic module, which prepares a sample for storageafter analytic testing (e.g., a recapper module, which reseals a sampletest tube); or a sample handling module. The function of a samplehandling module may include managing sample containers/vessels for thepurposes of inventory management, sorting, moving them onto or off of anautomation track (which may include an integral conveyance system,moving sample containers/vessels onto or off of a separate laboratoryautomation track, and moving sample containers/vessels into or out oftrays, racks, carriers, pucks, and/or storage locations.

Payload:

While exemplary carriers are described with respect to carrying patientsamples, in some embodiments, carriers can be used to transport anyother reasonable payload across an automation system. This may includefluids, fluid containers, reagents, waste, disposable items, parts, orany other suitable payloads.

Processor:

A processor may refer to one or more processors and/or related softwareand processing circuits. This may include single or multicoreprocessors, single or multiple processors, embedded systems, ordistributed processing architectures, as appropriate, for implementingthe recited processing function in each embodiment.

Pullouts, Sidecars, Offshoot Paths:

These terms may be used to refer to track sections that are off the mainportion of a track system. Pullouts or sidecars may include chords,parallel tracks, or other suitable means for separating some carriersfrom a primary traffic pattern. Pullouts or sidecars may be configuredto facilitate physical queues or allow certain carriers to stop or slowdown without disrupting traffic on a main track section.

Samples:

Samples refers to fluid or other samples taken from a patient (human oranimal) and may include blood, urine, hematocrit, amniotic fluid, or anyother fluid suitable for performing assays or tests upon. Samples maysometimes refer to calibration fluids or other fluids used to assist ananalyzer in processing other patient samples.

STAT (Short Turnaround Time) Sample:

Samples may have different priority assigned by a laboratory informationsystem (LIS) or operator to assign STAT priority to samples that shouldtake precedent over non-STAT samples in the analyzer. When usedjudiciously, this may allow certain samples to move through the testingprocess faster than other samples, allowing physicians or otherpractitioners to receive testing results quickly.

Station:

A station includes a portion of a module that performs a specific taskwithin a module. For example, the pipetting station associated with ananalyzer module may be used to pipette sample fluid out of samplecontainers/vessels being carried by carriers on an integrated conveyancesystem or a laboratory automation system. Each mModule can include oneor more stations that add functionality to a module.

Station/Module:

A station includes a portion of an analyzer that performs a specifictask within an analyzer. For example, a capper/decapper station mayremove and replace caps from sample vessels; a testing station canextract a portion of a sample and perform tests or assays; a samplehandling station can manage sample vessels, moving them onto or off ofan automation track, and moving sample vessels into or out of storagelocations or trays. Stations may be modular, allowing stations to beadded to a larger analyzer. Each module can include one or more stationsthat add functionality to an analyzer, which may be comprised of one ormore modules. In some embodiments, modules may include portions of, orbe separate from, an automation system that may link a plurality ofmodules and/or stations. Stations may include one or more instrumentsfor performing a specific task (e.g., a pipette is an instrument thatmay be used at an immunoassay station to interact with samples on anautomation track). Except where noted otherwise, the concepts of moduleand station may be referred to interchangeably.

Tubes/Sample Vessels/Fluid Containers:

Samples may be carried in vessels, such as test tubes or other suitablevessels, to allow carriers to transport samples without contaminatingthe carrier surfaces.

Exemplary Embodiments

The above problems in the prior art have motivated the discovery ofimproved apparatus and methods for reliably and/or automaticallytransporting samples between stations/testing modules within anautomated clinical analyzer (analyzer). Specifically, by providingsemi-autonomous carriers for samples, the carriers can transport samplessubstantially faster than prior methods, allowing reliable scheduling oftests, a reduction of traffic in the automation system, and reducedlatency and reliable throughput of tests within the analyzer. Someembodiments exploit the semi-autonomy of the sample carriers to providetransit between stations in less than a single operation cycle,effectively removing or greatly reducing automation of sample placementas a performance bottleneck, and allowing more flexible samplescheduling options.

Embodiments of the present invention include systems and methods thatprovide a more efficient lab automation system to allow samples to beshuttled between and amongst various analyzer testing stations with lesslatency and more individual control. Embodiments of the presentinvention can reduce or eliminate queues experienced by samplestraversing the automation system. Usually, samples need to undergo manydifferent types of testing in an automated clinical analyzer (analyzer),which may not be available in a single testing station. Testing stationswithin an analyzer can be adapted for specialized testing. For example,immunoassays may be performed by an immunoassay station that includescertain incubation capabilities and uses specific reagents that areunique to immunoassays. Chemical analysis can be performed by a clinicalanalyzer and electrolyte chemistry analysis can be conducted by anion-selective electrode (ISE) clinical analyzer. By using this modularapproach, an analyzer can be adapted not only to the types of testingbeing done on samples, but also the frequency and volume of testingnecessary to accommodate the needs of the lab. If additional immunoassaycapability is needed, a lab may choose to add additional immunoassaystations and increase overall throughput for immunoassay testing intheir system.

An exemplary track geometry, for use in transporting samples within ananalyzer typical in prior art configurations, is shown in FIG. 1. Thistrack can include prior art friction tracks, which may introduceproblems in designing a track system. However, certain embodiments ofthe present invention could also use a similar geometry withoutnecessarily employing a friction track for motion. Track 100 can be agenerally oval-shaped track that conveys samples in pucks or traysbetween various stations, such as sample preparation oranalyzing/testing stations 110, 120, and 130. Track 100 could be asingle direction track or, in some instances, a linear bidirectionaltrack. In this exemplary set-up, each analyzer 110, 120, 130 is servicedby a respective sidecar 112, 122, 132. At the junction between the track100 and each sidecar, a gate or switch can be placed that allows samplesto be diverted to or from track 100 to the sidecar. The oval nature oftrack 100 can be used to circulate samples while they wait for access toeach analyzer. For example, analyzer 110 may have a full queue insidecar 112, such that new samples on track 100 cannot be diverted topullout 112 until analyzer 110 finishes handling a pending sample insidecar 112 and inserts it back into the main traffic flow of track 100.

In some prior art systems, each sidecar can be serviced by a handlingmechanism such as sample probe arms 114, 124, and 134. These robotichandling arms can aspirate sample material from samples in a sidecar viaa probe needle, or can pick up a sample tube from the sidecar andtransport it into the corresponding testing station. In this exemplarysystem, the available testing stations include an immunoassay station110, a low-volume chemistry station 120, and an expandable dilution/ISEelectrolyte and high-volume chemistry station (or stations) 130. Someadvantages of this approach are that the track 100 can be part of aseparate lab automation system that can be added onto otherwiseself-contained stations, and the track 100 and stations 110, 120, and130 can be independently upgraded, purchased, or serviced. Somestations, such as high-volume chemistry station 130, can include theirown friction track 136 that operates independently of track 100.Friction track 136 can include a bidirectional friction track thatallows samples to move between sub-modules of high-volume chemistrystation 130. A drawback of this type of system is that the separatefriction tracks operate independently and control of overall automationbecomes more complicated. Furthermore, transitions between frictiontracks 136 and 100 can be slow and cumbersome, particularly where thereis no direct route between two friction tracks. In some systems, movingbetween tracks may require lifting and placing samples via a robot arm.

Prior art lab automation systems for analyzers generally treatindividual analyzer/testing stations as generic destinations for asample on the track. In some embodiments of the present invention, thelab automation system can be integrated within the individual testingstations, which can substantially reduce or eliminate the complexity ofthe individual testing stations and reduce the need for separate samplehandling systems within each station. In some embodiments, byintegrating the lab automation system into the stations, the system canbegin to treat individual stations less as generic destinations and moreas portions of a multi-route track onto which a sample can travel.

FIG. 2A shows one embodiment of a track system that can be adapted foruse with the present invention. Track 150 is a rectangular/oval/circulartrack on which sample carriers move in a clockwise (or counterclockwise)direction. Track 150 may be unidirectional or bidirectional. Carrierscan transport any suitable payload within an IVD environment, such asfluid samples, reagents, or waste. Fluids, such as patient samples, canbe placed in a container or vessel, such as a test tube, vial, cuvette,etc. that can be transported by a carrier. Carriers and, by extension,payloads such as samples, can move on the main track 150 or be divertedvia decision points such as 164 or 166. These decision points can bemechanical gates (as in the prior art) or other mechanisms suitable forallowing a sample to be diverted from the main track 150 to a sidecar,such as 160, 160A, 160B, 160C as described herein. By way of example, ifa sample carrier is traversing the main path 150 and reaches decisionpoint 166, it can be made to continue on the main track to segment 162or it can be made to divert to sidecar 160. The systems and methods bywhich the decision can be made to divert the sample carrier at decisionpoint 166 are described throughout.

FIG. 2B shows an alternative track layout that may be suitable forcertain embodiments of the present invention. Track 170 is also agenerally circular track with sample carriers moving clockwise (orcounterclockwise). In this example, rather than having sidecars outsideof the track, pullouts 180, 180A, and 180B are chords within the track.Similarly, when sample carriers reach decision points, they may bediverted off of the main path to a side path such as path 180. Atdecision point 186, a sample on the main track 170 can be made tocontinue on the main track or be diverted onto path 180. Once ananalyzer station along handling path 180 is done processing the sample,the sample proceeds to decision point 184 where it may be placed backonto the main path 170.

FIG. 3 shows a modular approach to the automation system track that canbe used for certain embodiments of the present invention. In thisexample, the tracks may be integrated into individual analyzer stations,such that the track can be used as part of the internal motion or samplehandling system of individual lab stations. In the prior art, it iscommon to have multiple different types of motion systems withindifferent analyzer/testing stations. For example, some stations caninclude friction tracks for shuttling pucks or trays of sample tubes,and may include carousels containing smaller vessels, such as cuvettesand reaction vessels, into which portions of the sample can be aspiratedand dispensed. In some embodiments, by integrating portions of the tracksystem into the analyzer stations themselves, each station can includeits own queuing logic and may be simplified to eliminate unnecessaryinternal motion systems.

With respect to FIG. 3, the track 200 can be broken into modularcomponents that are integrated into analyzer modules. In this exemplarytrack, modules 205, 205A, and 205B can be combined with one another andoptionally other modular track components 202 and 204 to form a tracksimilar to that shown in FIG. 2B. For instance, 205A can be a modulethat performs the same function as immunoassay 110 (FIG. 1), 205 can bea module that performs the same function as low-volume chemistry module120 (FIG. 1), and 205B can be a module that performs ISE electrolytetesting, like module 130 (FIG. 1). In this example, the main outer trackcan be formed by track segments 202, 204, 206, 206A, 206B, 208, 208A,and 208B. Within the analyzer modules 205, 205A, and 205B, internalpaths 210, 210A, and 210B form pullouts from the main track. Theinternal paths can be used for internal queuing and can be managedindependently within each analyzer module to allow each module to havegreater control over samples to be processed.

One advantage of integrating track 200 and sub-paths 210, 210A, and 210Binto the analyzer modules 205, 205A, and 205B, respectively, is that theinternal handling mechanisms within each analyzer module can bespecially adapted to better coordinate with the track sub-paths. In someembodiments, modules 205, 205A, and 205B can be adapted to process eachsample within a period that is less than an operation cycle of theoverall analyzer, leaving enough time for the sample to be routed alongthe track system to another module after processing, allowing the othermodule to immediately process the sample on the next operation cycle. Asused herein, an operation cycle is a unit of time used by schedulingalgorithms to allot processing time to modules for sample assays. Thesecan be dynamic or fixed and can allow synchronous operation of themodules in the analyzer and provide a reliable timing model forscheduling samples amongst multiple modules in the analyzer. Theoperation cycle time can be chosen to be the time needed by any givenmodule between when it starts processing a first sample, and when it isready to process another sample under expected steady-state conditions.For example, if an analyzer can process one test every three seconds,and the expected average tests per sample is seven, the operation cycletime can be 21 seconds. It should be understood that individual modulescan implement efficiency techniques, such as parallelism or processingmultiple samples within a cycle, to maximize throughput, even when thenumber of tests-per-sample varies from an expected amount. Furthermore,it should be understood that in some embodiments, individual moduleshave different operation cycle times, and these modules can operatesubstantially asynchronously from one another. Virtual queues or bufferscan be used to assist the management of sample scheduling where cycletimes or demand vary between modules.

Enabling transit between modules in the analyzer in a reliable timeframe, on the order of a single operation cycle or less, achieves manyperformance advantages not possible with prior art track systems. If asample can be reliably handled by an analyzer module and transported tothe next analyzer module within a single cycle of the analyzer, traffichandling in queuing becomes much simpler, throughput becomes moreconsistent, and latency can be controlled and reduced. Essentially, insuch an analyzer, a sample can reliably be handled by the track systemand processed uniformly such that a sample does not sit idly on thetrack system waiting in queues. Furthermore, queues within the system,such as queues within a given analyzer module, can reliably beshortened, limited by the number of modules within the system.

In some embodiments of the present invention, the reliable and rapidnature of the track system enables queues to be virtual, rather thanphysical. A virtual queue can be handled in software, rather than byphysical limitations. Traditionally, queues have been physical. Thesimplest physical queue is effectively a traffic jam at any given partof a sample handling operation. A bottleneck creates a first-infirst-out (FIFO) queue, where sample carriers are effectively stopped ina line, providing a buffer so that an analyzer or a decision point canrequest the next sample in the queue when it is ready. Most prior artlab automation tracks maintain FIFO processing queues to buffer samplesthat are waiting to be processed by the attached modules (analyzers orpre/post analytic devices). These buffers allow the track to processsample tubes at a constant rate, even though the modules or operatorrequests can create bursts of demand. FIFO queues can also substantiallyincrease the throughput of the individual modules by allowing them toperform preprocessing tasks for future samples, for example, prepare acuvette or aspirate reagent, while processing the current sample. Whilethe rigid predictability of FIFO queues enables the parallelization ofsome processing tasks, it also can prevent the modules from usingopportunistic scheduling that may increase throughput by reorderingtests on samples to optimize resources. For example, the internalresource conflicts of most immunoassay analyzers can be so complex thatthe analyzers need to interleave the tests from multiple samples inorder to reach maximum efficiency. A FIFO queue can reduce thethroughput of these analyzers by as much as 20%. Another challenge withFIFO queues is their inability to handle priority samples (e.g., a STATsample). If a STAT sample needs to be processed immediately, the entireFIFO queue has to be flushed back onto the main track, delaying allother samples on the track and forcing the original module to slowlyrebuild its queue.

Another type of queue is a random access (RA) queue. A carousel is anexample of a physical RA queue found in analyzer modules. By aliquotinga portion of a sample into one or more vessels in a carousel ring, ananalyzer module can select any of a number of samples to process at anytime within the analyzer. However, carousels have many drawbacks,including added complexity, size, and cost. A carousel also increasesthe steady-state processing time, because a sample must be transferredinto and out of the random-access queue. Processing delays depend on theimplementation, such as the number of positions in a carousel. On theother hand, by having random access to samples, a local schedulingmechanism within a module can process samples in parallel, performingsub-steps in any order it desires.

In some embodiments, carousels or other RA queues can be eliminated fromthe modules and the sub-paths (e.g., 210) from the automation system canbe used as part of an RA or FIFO queue. That is, if the travel time fora sample between any two points can be bounded to a known time that issimilar to that of a carousel (such as predictably less than a portionof an operation cycle), the track 200 can be part of the queue for agiven module. For example, rather than using a carousel, module 205 canutilize samples in carriers on sub-path 210. Preprocessing steps, suchas reagent preparation, can be conducted prior to the arrival of asample under test. Once that sample under test arrives, one or moreportions of the sample can be aspirated into cuvettes or other reactionvessels for an assay. In some embodiments, these reaction vessels can becontained within module 205, off track, while in other embodiments,these reaction vessels can be placed in carriers on sub-path 210 toallow easy motion. If the sample under test is required to be at amodule for longer than an operation cycle, or if multiple samples willbe processed by the module during an operation cycle, the sub-path 210can act as a queue for the module.

Furthermore, samples not yet under test, which may be currently locatedat other modules, can be scheduled for the next operation cycle. Thesenext-cycle samples can be considered as residing in a virtual queue formodule 205. A module can schedule samples to arrive during a givenoperation cycle for any sample on track 200. A central controller, orcontrollers associated with modules themselves, can resolve anyconflicts over a sample for a given cycle. By giving a module priorknowledge of the arrival time of a sample, each module can prepareresources and interleave tests or portions of tests to more efficientlyallot internal resources. In this manner, modules can operate on samplesin a just-in-time manner, rather than by using large physical buffers.The effect is that the virtual queue for a given module can be muchlarger than the physical capacity of the sub-path serving that module,and existing scheduling algorithms can be used. Effectively, each modulecan treat track 200 as it would treat a sample carousel in a prior artmodule.

It should be appreciated that by employing virtual queues, in someembodiments, multiple modules can have multiple queues and can share asingle queue or samples within a queue. For example, if two modules areequipped to perform a certain assay, a sample needing that assay can beassigned to a virtual queue for that assay, which is shared between thetwo modules capable of handling the assay. This allows load balancingbetween modules and can facilitate parallelism. In embodiments wherereaction vessels are placed in carriers on track 200, an assay can bestarted at one module (e.g., reagents prepared and/or sample mixed in)and the assay can be completed at another (e.g., a reaction is observedat another module). Multiple modules can effectively be thought of as amulti-core processor for handling samples in some embodiments. In theseembodiments, scheduling algorithms for the multiple modules should becoordinated to avoid conflicts for samples during a given operationcycle.

By employing virtual queues, modules can operate on samples while thesamples are in the virtual queues of other modules. This allows lowlatency of samples, as each sample that is placed onto track 200 can beprocessed as quickly as the modules can complete the tests, withouthaving to wait through a physical queue. This can greatly reduce thenumber of sample carriers on track 200 at any given time, allowingreliable throughput. By allowing modules to share queues or samples,load balancing can also be used to maximize throughput of the system.

Another advantage of using virtual queues is that STAT samples can bedynamically assigned priority. For example, a STAT sample can be movedto the head of any queue for the next operation cycle in software,rather than having to use a physical bypass to leapfrog a STAT sample tothe head of a largely static physical queue. For example, if a module isexpecting three samples to be delivered by track 200 for assays duringthe next operation cycle, a scheduler responsible for assigning samplesto the module can simply replace one or more of the samples with theSTAT sample, and have the track 200 deliver the STAT sample forprocessing during the next operation cycle.

If decision points such as 214 and 216 can be streamlined such thatthere is no need for a queue at each decision point, the only physicalqueues can be within sub-paths 210, 210A, and 210B. As described above,these can be treated as RA queues or FIFO queues. If a STAT sample isplaced onto track 200, RA queues within sub-paths 210, 210A, and 210Bneed not be flushed, as the STAT sample can be processed immediately.Any FIFO queues can be individually flushed. For example, if a STATsample is placed onto track 200 at section 222, the sample may be routedto the appropriate analyzer 205B via the outside track and decisionpoint 216. If there are other samples (and, by extension, the samplecarriers transporting those samples) waiting in the queue in path 210B,only those samples in the queue may need to be flushed to allow a STATsample to take priority. If the outer track 200 is presumed to take lessthan an operation cycle to traverse, any samples that were flushed fromthe queue in 210B can simply be circulated around the track and placedimmediately back into the queue in path 210B immediately behind the STATsample, eliminating any down time caused by the STAT sample.

Entry paths 220 and 222 can be used to input samples to the track 200.For example, regular priority samples can be placed onto track 200 atinput 220 and STAT priority samples can be placed on input 222. Theseinputs can be used as outputs for samples when complete, or other ports(not shown) can be used as the output paths for used samples. Input 220can be implemented as an input buffer, acting as a FIFO queue for inputsamples seeking access to the track 200. Once a sample reaches the headof the queue at input 220, it can be moved onto the track (either bybeing placed in a carrier, or by being placed in a carrier when it isplaced in input 220). A STAT sample can enter the track 200 immediatelyafter being placed at input 222 or, if track 200 is overcrowded, theSTAT sample can enter the track at the next available uncrowdedoperation cycle. Some embodiments monitor the number of carriers on thetrack during an operation cycle and limit the total number to amanageable amount, leaving the remainder in input queues. By restrictingsamples at the input, track 200 can be free of traffic, allowing it toalways be operated in the most efficient manner possible. In theseembodiments, the transit time of a sample between two modules can be abounded value (e.g., less than some portion of an operation cycle),allowing simplified scheduling.

In some embodiments, the track system 200 can be designed to bebidirectional. This means that sample carriers can traverse the outsidepath and/or any sub-paths in either direction. In some embodiments,additional sub-paths, such as 211B accessed via additional decisionpoints 215 and 217, can assist in providing bidirectional access.Bidirectional paths can have inherent advantages. For example, if normalpriority samples are always handled in the same direction, a STAT samplecan be handled in the opposite direction along the sub-path. This meansthat a STAT sample can essentially enter the exit of the sub-path and beimmediately placed at the head of the queue without requiring the queueto be flushed. For example, if a STAT sample is placed on track 200 atsegment 204, it can enter path 210B via decision point 214 and proceedinto path 210B to be immediately placed at the head of any queue.Meanwhile, in all of these examples, because queues are presumed to belimited generally to sub-paths, there is no need to flush queues inother modules if a STAT sample does not need immediate access to thosemodules. Any additional modules that need to service a STAT sample on asubsequent cycle can flush their queues at that point, providingjust-in-time access to a STAT sample without otherwise disrupting theoperation of each analyzer module.

Modular design also allows certain other advantages. If the automationsystems within an analyzer module are adapted to take advantage of thetrack system contained in the module, new features can be added that usethe common track. For example, a module could have its own internalreagent carousel that includes all of the reagents necessary forperforming the assays prescribed for the samples. When reagents stockedin the analyzer module run low, an operator can replenish the reagentsin some embodiments by simply loading additional reagents onto carrierson the track 200. When the reagents on track 200 reach the appropriatemodule, the module can utilize mechanical systems such as an arm or afeeder system that takes the reagents off of the track and places thereagents in the reagents store for the module.

In some embodiments, the individual track portions shown in FIG. 3 andFIG. 2A and FIG. 2B can be operated independently from one another, orcan be passive. Independent carrier movement provides advantages overfriction-based track systems, such as non-localized conveyor belts wherethe entire friction track must be moved to effect movement of a samplecarrier. This means that other samples also on that track must move atthe same rate. This also means that if certain sections operate atdifferent speeds, collisions between passive carriers carrying samplescan occur.

FIG. 4A depicts an exemplary carrier 250 for use with the presentinvention. Carrier 250 can hold different payloads in differentembodiments. One payload can be a sample tube 255, which contains afluid sample 256, such as blood or urine. Other payloads may includeracks of tubes or reagent cartridges, or any other suitable cartridge.Sample carrier 250 includes a main body 260, which can house theinternal electronic components describe herein. The main body 260supports a bracket 262, which can accept a payload. In some embodiments,this is a shallow hole that is designed to accept a fluid container 255such as a sample tube, and hold it with a friction fit. In someembodiments, the friction fit can be made using an elastic bore or aclamp that can be fixed or energized with a spring to create a holdingforce. In some embodiments, sample racks and reagent cartridges can bedesigned to also attach to the bracket 262, allowing bracket 262 to actas a universal base for multiple payload types.

Body 260 can include or be coupled to guide portion 266, which allowsthe carrier 250 to follow a track between decision points. Guide portion266 can include, for example, a slot to accept one or more rails in thetrack, providing lateral and/or vertical support. In some embodiments,the guide portion allows the carrier 250 to be guided by walls in thetrack, such as the walls of a trough-shaped track. The guide portion 266can also include drive mechanisms, such as friction wheels that allow amotor in the carrier body 260 to drive the carrier or puck 250 forwardor backward on the track. The guide portion 266 can include other drivecomponents suitable for use with the embodiments described throughout,such as magnets or induction coils.

Rewritable display 268 can be provided on the top of the carrier 250.This display can include an LCD oriented panel and can be updated inreal time by the carrier 250 to display status information about sample256. By providing the electronically rewritable display on the top ofthe carrier 250, the status information can be viewed at a glance by anoperator. This can allow an operator to quickly determine which samplehe/she is looking for when there are multiple carriers 250 in a group.By placing the rewritable display on top of the carrier 250, an operatorcan determine status information even when multiple carriers 250 are ina drawer or rack.

FIG. 4B shows an exemplary track configuration 270 for use by carriers250. In this example, carriers 250A transport sample tubes, whilecarriers 250B transport racks of tubes along main track 272 and/orsubpaths 274 and 274A. Path 276 can be used by an operator to placesamples into carriers or remove samples from these carriers.

FIG. 4C shows an additional view of an exemplary track configuration270. In this example, sub-path 274 serves an immunoassay station, whilesub-path 274A serves a clinical chemistry station. Input/output lane 276can be served by a sample handler station 280 that uses sub-paths 277and 278 to buffer samples for insertion or removal of the samples fromthe main track 272.

In some embodiments, the sample handler 280 can also load and unloadsamples or other payloads to/from the carriers 250A and 250B. Thisallows the number of carriers to be reduced to the amount needed tosupport payloads that are currently being used by the stations in tracksystem 270, rather than having a vast majority of carriers sitting idleon tracks 277 and 278 during peak demand for the analyzer. Instead,sample trays (without the carriers disclosed herein) can beplaced/removed by an operator at input/output lane 276. This can reducethe overall cost of the system and the number of carriers needed can bedetermined by the throughput of the analyzer, rather than based onanticipating the peak demand for the analyzer in excess of throughput.

Intelligent Carriers

Whereas prior art lab automation systems utilize passive pucks or trays(e.g., the puck is a simple plastic or rubber brick that lacks active orautonomous systems, power, onboard processing, or control) to reducecost and complexity, the inventors of the present invention haverealized that the added complexity and cost necessary to integrateintelligence and autonomy into individual carriers (which can includeintelligent pucks or trays in some embodiments) provides unexpected andimportant benefits that have been overlooked in traditional labautomation systems. Accordingly, embodiments of the present inventioncan utilize intelligent independent carriers to enable certainimprovements over passive pucks on friction-based tracks. For example,one disadvantage of prior art track systems is that at each decisionpoint the decision for directing a puck is made by the track by rotatingthe puck and reading a barcode optically. Rotating and optical readingis a relatively slow process. Furthermore, this process can be redundantbecause the system has knowledge of the identification of the sampletube when the sample tube is placed into the puck by an operator.Embodiments of the present invention can include carriers that havemeans to identify the contents of the sample tube (and optionallycommunicate this information to the automation system) without requiringthe carrier to be stopped, rotated, and read optically.

For example, a carrier can include an onboard optical reader toautomatically read a barcode of a payload. The results of the scan canthen be stored in the memory of a carrier if the carrier has onboardprocessing capability. Alternatively, an outside source, such as a handbarcode reader operated by an operator at the time of placing the sampleinto the carrier, can communicate the barcode information of the payloadto the carrier via RF signal or other known means, such as communicationprotocol using temporary electrical contact or optical communication. Insome embodiments, the association of the carrier with the payload can bestored external to the carrier and the identity of the carrier can beconveyed by the carrier to the system by RF, optical, or near fieldcommunication, allowing the system to assist in routing or tracking thecarrier and the payload. Routing decisions can then be made by thecarrier or by identifying the carrier, rather than reading a uniquebarcode of a payload.

By moving processing capability and/or sensor capability onto eachindividual carrier, the carriers can participate actively andintelligently in their own routing through the track system. Forexample, if individual carriers can move independently of one anothereither by autonomous motive capabilities or by communication with thetrack, certain performance advantages can be realized.

By allowing carriers to move independently, carriers can move around thetrack faster. One key limitation on the motion of a carrier is that itshould not spill an open-tube sample. The limiting factor is generallynot the velocity of the carrier in a straight line, but the accelerationand jerk experienced by the carrier (while speeding up, slowing down, orturning), which may cause splashing. For prior-art friction-based tracksystems, the velocity of the track is typically limited to preventacceleration and jerk experienced by pucks from exceeding thresholdamounts because the entire track moves. However, by using a track systemwith independently operating sections that can respond to individualcarriers, or individual carriers that have independent motivecapability, the acceleration of any given carrier can be tailored tolimit acceleration/deceleration and jerk, while allowing the averagevelocity to be greater than that of traditional tracks. By not limitingthe top speed of a carrier, the carrier can continue to accelerate oneach track section as appropriate, resulting in a substantially higheraverage speed around the track. This can assist the carrier intraversing the entire track system in less than one machine cycle of theanalyzer. These machine cycles can be, for instance 20 or 40 seconds.

Similarly, an autonomous carrier can know its own identity and that ofits payload. This allows the carrier to actively participate or assistin the routing decision process at individual decision points. Forexample, upon reaching a decision point (e.g., switch, intersection,junction, fork, etc.), a carrier can communicate its identity and/or theidentity of its payload to the track or any switching mechanism (or itsintended route that the carrier has determined based on the payloadidentity), via RF or near field communication. In this scenario, thecarrier does not need to be stopped at a decision point for a barcodescan. Instead, the carrier can keep going, possibly without even slowingdown, and the carrier can be routed in real time. Furthermore, if thecarrier knows where it is going or communicates its identity to thetrack (such that the track knows where the carrier is going) before thecarrier physically reaches a decision point, the carrier can be made todecelerate prior to a decision point if the carrier will be turning. Onthe other hand, if the carrier does not need to turn at the decisionpoint, the carrier can continue at a higher velocity because the samplecarried by the carrier will not undergo cornering forces if the carrieris not turning at the decision point or a curved section of the track.

An autonomous carrier can also include onboard processing and sensorcapabilities. This can allow a carrier to determine where it is on thetrack and where it needs to go, rather than being directed by the track(although, in some embodiments, a central controller sends routinginstructions to the carrier to be carried out). For example, positionencoding or markers in the track can be read by a carrier to determinethe carrier's location. Absolute position information can be encoded ona track surface to provide reference points to a carrier as it traversesthe track. This position encoding can take many forms. The track may beencoded with optical markers that indicate the current section of thetrack (e.g., like virtual highway signs), or may further include opticalencoding of the specific absolute location within that section of track(e.g., like virtual mile markers). Position information can also beencoded with markings between absolute position marks. These can providesynchronization information to assist a carrier in reckoning its currenttrajectory. The optical encoding scheme may take on any appropriate formknown to one skilled in the art. These marks used by the encoding schememay include binary position encoding, like that found in a rotaryencoder, optical landmarks, such as LEDs placed in the track at certainpositions, barcodes, QR codes, data matrices, reflective landmarks, orthe like. General position information can also be conveyed to thecarrier via RF/wireless means. For example, RFID markers in the trackcan provide near field communication to the carrier to alert the carrierthat it has entered a given part of the track. In some embodiments,local transmitters around or near the track can provide GPS-likepositioning information to enable the carrier to determine its location.Alternatively, sensors in the track, such as Hall effect sensors orcameras, can determine the position of individual carriers and relaythis information to the carrier.

Similarly, the carrier can have sensors that indicate relative motion,which provide data that can be accumulated to determine a position. Forexample, the carrier may have gyroscopes, accelerometers, or opticalsensors that observe speckle patterns as the carrier moves to determinevelocity or acceleration, which can be used to extrapolate a relativeposition.

Because a carrier can know where it is and its motion relative to thetrack, a carrier can essentially drive itself, provided it knows itsdestination. The routing of the carrier can be provided in manydifferent ways in various embodiments. In some embodiments, when acarrier is loaded with the sample, the system can tell the carrier thedestination analyzer station. This information can be as simple as theidentification of the destination station in embodiments where thecarrier has autonomous routing capability. This information can also bedetailed information such as a routing list that identifies the specificpath of the individual track sections and decision points that a carrierwill traverse. Routing information can be conveyed to the carrier viaany communication method described herein, such as RF communication,near field/inductive communication, electrical contact communication, oroptical communication.

In an exemplary embodiment, when an operator scans the barcode of thesample tube and places it in a carrier, the system determines theidentity of the carrier and matches it with the identity of the sample.The system then locates the record for the sample to determine whichtests the sample must undergo in the analyzer. A scheduler thenallocates testing resources to the sample, including choosing whichtests will be done by individual testing stations and when the sampleshould arrive at each testing station for analysis. The system can thencommunicate this schedule (or part of the schedule) to the carrier toinform the carrier of where it needs to go, and optionally when it needsto go and/or when it needs to arrive.

Once the carrier is placed onto the track system, the routingcapabilities and location acquisition systems of the carrier enable thecarrier to determine where it is on the track and where it needs to goon the track. As the carrier traverses the track, the carrier reachesindividual decision points and can be directed along the main track oralong sub-paths as appropriate. Because each carrier operatesindependently from one another, a carrier can do this quite quicklywithout necessarily stopping at each decision point and without waitingfor other carriers in a queue. Because these carriers move quickly,there is less traffic on the main sections of the track, which reducesthe risk of collision or traffic jams at decision points or corners inthe track (e.g., sections where carriers might slow down to avoidexcessive forces on the sample).

Motive force can be provided to the carriers in many ways. In someembodiments, the track actively participates in providing individualizedmotive force to each carrier. In some embodiments, motive force isprovided by electromagnetic coils in the track that propel one or moremagnets in the carrier. An exemplary system for providing this motiveforce is the track system provided by MagneMotion, Inc., which cangenerally be understood by the description of the linear synchronousmotors (LSMs) found in US Published Patent Application 2010/0236445,assigned to MagneMotion, Inc. These traditional systems utilizing thismagnetic motion system have included passive carriers that lack theintegrated intelligence of the carriers described herein, and allrouting and decisions are made by a central controller with no need foractive carriers that participate in the routing and identificationprocess.

In embodiments that utilize magnetic motion, the electromagnetic coilsand the magnets operate as an LSM to propel each individual carrier inthe direction chosen with precise control of velocity, acceleration, andjerk. Where each coil on the track (or a local set of coils) can beoperated independently, this allows highly localized motive force toindividual carriers such that individual carriers can move with theirown individually tailored accelerations and velocities. Coils local to acarrier at any given moment can be activated to provide precise controlof the direction, velocity, acceleration, and jerk of an individualcarrier that passes in the vicinity of the coils.

In some embodiments, a track may be comprised of many individuallyarticulable rollers that act as a locally customizable friction track.Because individual micro-sections of the track can be managedindependently, rollers immediately around a carrier may be controlled toprovide individualized velocity, acceleration, and jerk. In someembodiments, other active track configurations can be used that providelocalized individual motive force to each carrier.

In some embodiments, the track may be largely passive, providing afloor, walls, rails, or any other appropriate limitations on the motionof a carrier to guide the carrier along a single dimension. In theseembodiments, the motive force is provided by the carrier itself. In someembodiments, each individual carrier has one or more onboard motors thatdrive wheels to provide self-propelled friction-based motive forcebetween the track and the carrier. Unlike traditional friction tracks,where the track is a conveyor, carriers with driven wheels can traversethe track independently and accelerate/decelerate individually. Thisallows each carrier to control its velocity, acceleration, and jerk atany given moment to control the forces exerted on its payload, as wellas traverse the track along individually tailored routes. In someembodiments, permanent magnets may be provided in the track andelectromagnets in the carrier may be operated to propel the carrierforward, thereby acting as an LSM with the carrier providing the drivingmagnetic force. Other passive track configurations are alsocontemplated, such as a fluid track that allows carriers to float andmove autonomously via water jets or the like, a low friction track thatallows carriers to float on pockets of air provided by the track, (e.g.,acting like a localized air hockey table), or any other configurationthat allows individual carriers to experience individualized motiveforces as they traverse the track.

FIG. 5 shows a top-level system diagram of the control systems andsensors for an exemplary intelligent autonomous carrier 300. Carrier 300is controlled by a microcontroller 301 that includes sufficientprocessing power to handle navigation, maintenance, motion, and sensoractivities needed to operate the carrier. Because the carrier is activeand includes onboard electronics, unlike prior art passive carriers, thecarrier includes an onboard power station. The details of this stationvary in different embodiments of the present invention. In someembodiments, power system 303 comprises a battery that may be charged asthe carrier operates, while in other embodiments, the battery isreplaceable or can be manually charged when the carrier is notoperating. Power system 303 can include the necessary chargingelectronics to maintain a battery. In other embodiments, power system303 comprises a capacitor that may be charged by inductive or electricalcontact mechanisms to obtain electrical potential from the track itself,in much the same way a subway car or model train might receive power.

Microcontroller 301 communicates with system memory 304. System memory304 may include data and instruction memory. Instruction memory inmemory 304 includes sufficient programs, applications, or instructionsto operate the carrier. This may include navigation procedures as wellas sensor handling applications. Data memory in memory 304 can includedata about the current position, speed, acceleration, payload contents,navigational plan, identity of the carrier or payload, or other statusinformation. By including onboard memory in carrier 300, the carrier cankeep track of its current status and uses information to intelligentlyroute around the track or convey status information to the track orother carriers.

Microcontroller 301 is responsible for operating the motion system 305,sensors 312, 313, and 314, communication system 315, status display 316,and sample sensor 317. These peripherals can be operated by themicrocontroller 301 via a bus 310. Bus 310 can be any standard bus, suchas a CAN bus, that is capable of communicating with the plurality ofperipherals, or can include individual signal paths to individualperipherals. Peripherals can utilize their own power sources or thecommon power system 303.

Motion system 305 can include the control logic necessary for operatingany of the motion systems described herein. For example, motion system305 can include motor controllers in embodiments that use driven wheels.In other embodiments, motion system 305 can include the necessary logicto communicate with any active track systems necessary to provide amotive force to the carrier 300. In these embodiments, motion system 305may be a software component executed by microcontroller 301 andutilizing communication system 315 to communicate with the track.Devices such as motors, actuators, electromagnets, and the like, thatare controlled by motion system 305 can be powered by power system 303in embodiments where these devices are onboard the carrier. Externalpower sources can also provide power in some embodiments, such asembodiments where an LSM provides motive force by energizing coils inthe track. In some embodiments, motion system 305 controls devices on oroff the carrier to provide motive force. In some embodiments, the motionsystem 305 works with other controllers, such as controllers in thetrack, to coordinate motive forces, such as by requesting nearby coilsin the track be energized or requesting the movement of local rollers.In these embodiments, motion system 315 can work together withcommunication system 315 to move the carrier.

Carrier 300 can include one or more sensors. In some embodiments,carrier 300 includes a collision detection system 312. Collisiondetection system 312 can include sensors at the front or back of acarrier for determining if it is getting close to another carrier.Exemplary collision detection sensors can include IR range-finding,magnetic sensors, microwave sensors, or optical detectors. Whereas manyprior art pucks are round, carrier 300 may be directional, having afront portion and a rear portion. By having a directional geometry,carrier 300 can include a front collision detector and a rear collisiondetector.

In some embodiments, collision detection information can includeinformation received via the communication system 315. For example, insome embodiments, the central controller for the track can observe thelocation and speed of carriers on the track and evaluate collisionconditions and send updated directions to a carrier to prevent acollision. In some embodiments, nearby carriers can communicate theirpositions in a peer-to-peer manner. This allows carriers to individuallyassess the risk of collision based on real-time position informationreceived from other carriers. It will be understood that in embodimentswhere the carrier receives trajectory information about other carriers,or decisions are made with the help of a centralized controller that hasaccess to trajectory information of nearby carriers, the carriers neednot be directional, and can include sensors or receivers that do notdepend on a given orientation of a carrier.

Carrier 300 can also include a position decoder 313. This sensor canextrapolate the carrier's position as described herein. For example,position decoder 313 can include a camera or other optical means toidentify landmarks in the track, or observe optical encoding in thetrack. In some embodiments, position decoder 313 can also includeinertial sensors, magnetic sensors, or other sensors sufficient todetermine a carrier's current position, direction, velocity,acceleration, and/or jerk.

Carrier 300 can optionally include a barcode reader 314. If equippedwith barcode reader 314, carrier 300 can observe the barcode of itspayload at the time the samples are loaded onto the carrier or at anytime thereafter. This prevents the need for a carrier to stop atindividual decision points to have the system read the barcode of asample tube. By reading and storing the identity of the sample tube, orconveying this information to the overall system, a carrier may moreefficiently traverse the track system because routing decisions can bemade in advance of reaching a decision point. Alternatively, where asystem knows the identity of the sample when it is placed onto thecarrier, the system can include an external barcode reader and canconvey the identity of the payload to the carrier for storage and memory304 via communication system 315.

Communication system 315 can comprise any mechanisms sufficient to allowthe carrier to communicate with the overall automation system. Forexample, this can include an XBee communication system for wirelesscommunication using an off-the-shelf communication protocol, such as802.15.4, any appropriate version of 802.11, or any standard orproprietary wireless protocol. Communication system 315 can include atransceiver and antenna and logic for operating an RF communicationprotocol. In some embodiments, communication system 315 can also includenear field communication, optical communication or electrical contactcomponents. Information conveyed via the communications system to/fromcarrier 300 is described throughout this application.

In some embodiments, the carrier can also include a status displaymodule 316. The status display module 316 can include a controller andrewritable electronic display, such as an LCD panel or E-ink display. Insome embodiments, the controller is treated as an addressable portion ofmemory, such that the microcontroller 301 can easily update the statusdisplay 316.

In some embodiments, the carrier also includes sample sensor 317. Thissensor can be used to indicate the presence or absence of a fluidcontainer in the carrier's tube bracket (which may also be referred toas a tube holder). In some embodiments, this is a momentary mechanicalswitch that is depressed by the presence of a tube and not depressedwhen a tube is absent. This information can be used to determine thestatus of a tube, which can assist in the display of status informationby status display module 316.

Routing

The desire for rapid transit times within an analyzer system can makerouting difficult. In prior art systems, rapid routing is less criticalbecause samples are generally stopped, singulated, and scanned at eachdecision point. In those systems, the routing decision for a givendecision point can be made while the sample is stopped. Rapid routingdecisions are generally desired, and may require determining a switchingdecision before a sample carrier reaches a decision point. Furthermore,because the carriers move at a rapid rate compared to the prior art, thecontrol of the instantaneous trajectory of a sample carrier can beassisted by real-time processing in order to prevent spilling ordamaging IVD samples. In some embodiments, substantially instantaneoustrajectory observation and control is conducted onboard each carrier tofacilitate real-time control, while the overall routing decisions aremade by a central controller that manages a group of carriers.Therefore, in some embodiments of the present invention, the carriersact like semi-autonomous robots that receive global routing instructionsfrom a central controller, but make local motion decisions substantiallyautonomously.

For example, when a carrier receives a sample (e.g., a patient fluidsample or other payload) a central controller managing one or morecarriers determines the schedule for that carrier and instructs thecarrier where to go on the track of, for example, an in vitrodiagnostics automation system. This instruction can be a next-hopinstruction (e.g., identifying the next leg of a route), such as goingto a given decision point, moving forward to the next decision point, orturning at a given decision point. In some embodiments, the instructionscan include a complete or partial list of track segments and decisionpoints to be traversed and whether to turn at each decision point. Theseinstructions can be communicated to the carrier from a centralcontroller via any conventional means, including wireless or contactelectrical signaling, as explained throughout this disclosure.

While following the instructions, each carrier can make a determinationof the appropriate velocity, acceleration, and jerk (as used herein,acceleration includes deceleration). This can include a real-timedecision of whether the carrier must slow down to avoid collision or toenter a curve without causing excessive lateral forces, or slow downbefore the next decision point. These decisions can be made with theassistance of any onboard sensors, as well as external informationreceived by the carrier, such as information about the position andtrajectory of nearby carriers. For example, accelerometers and/or trackencoding information can be used to determine the current velocity,acceleration, and jerk, as well as the current position of a carrier.This information can be used by each carrier to determine its trajectoryand/or can be conveyed to other carriers. Collision detectors, such asRF rangefinders, can determine whether or not a potential collisioncondition exists to assist the carrier in determining whether it needsto slow down and/or stop. This collision determination can includetrajectory information about the current carrier, as well as thetrajectory information about surrounding carriers received by thecurrent carrier through observation or by receiving information from acentral scheduler for the track.

FIG. 6 shows an exemplary routing scenario in automation system 400.Carrier 430 receives routing instructions from central managementprocessor 440 via RF signaling. Central management processor 440 canparticipate in monitoring and directing carriers, including issuingrouting instructions and scheduling the movement and dispatch ofcarriers. Central management processor 440 can be part of the centralcontroller and/or local controllers that interact with individualmodules or situations. Central or local controllers can also act at thedirection of central management processor 440. Central managementprocessor 440 can include one or more processors operating together,independently, and/or in communication with one another. Centralmanagement processor 440 can be a microprocessor, software operating onone or more processors, or other conventional computer means suitablefor calculating the schedule for multiple carriers within the tracksystem 400.

Central management processor 440 can receive position information frommultiple carriers, as well as any sensor information from sensors in thetrack system 400 and/or information reported by the carriers. Centralmanagement processor 440 uses the status information of the carriers andtrack as well as the identity of samples or other payload carried by thecarriers and the required assays to be performed by the system on thesesamples.

The exemplary track 400 shown in FIG. 6 includes a first curve segmentA, that connects to straight segment B and a pullout segment G (e.g., asegment that serves a testing station), which serves analyzer/testingstation 205A and pipette 420, via decision point 402. Segment B connectsto straight segment C and a pullout segment H, which servesanalyzer/testing station 205 and pipette 422, via decision point 404.Segment C connects to curved segment D, which serves sample handlingstation 205C, and pullout segment I, which serves analyzer/testingstation 205B and pipette 424, via decision point 406. Segment D connectsto straight segment E and the other end of pullout segment I, viadecision point 408. That is, there are different paths between decisionpoints 406 and 408—segments D and I (where segment I is a pullout thatcan be used to deliver samples to interact with pipette 424). Segment Econnects to straight segment F and the other end of pullout segment H,via decision point 410. Segment F connects to curved segment A and theother end of pullout segment G, via decision point 412. In someembodiments, track 400 includes input and output lanes J and K, whichcan be used to add or remove carriers at decision points 402 and 412.

In some embodiments, decision points 402-412 are passive forks in thetrack that carrier 430 can navigate to select a proper destinationsegment. In other embodiments, decision points 402-412 are active forksthat can be controlled by carrier 430 or central management processor440. In some embodiments, decision points 402-412 areelectromagnetically controlled switches that respond to requests bycarrier 430, such as via RF or near field communication. In someembodiments these electromagnetically controlled switches have a defaultposition, such as straight, that the switch will return to once acarrier has been routed. By using default positions for decision points,a carrier may not need to request a position at each decision point,unless it needs to be switched at that decision point.

Scheduler central management processor 440 assigns carrier 430 a firstroute, Route 1, to place the carrier 430 and its payload within reach ofpipette 420. Carrier 430 is instructed to travel along segment J todecision point 402 and travel onto segment G to stop at a positionaccessible to pipette 420. In some embodiments, carrier 430 receives theinstructions and determines its current location and trajectory todetermine a direction and trajectory to use to reach decision point 402.Carrier 430 can also take into account that it will be making a hardright turn at decision point 402 onto segment G. In some embodiments,decision point 402 includes a switching mechanism in the track that canoperate under the control of carrier 430. In these embodiments, carrier430 communicates with the track on approach to decision point 402 torequest switching onto segment G. In other embodiments, carrier 430 mayhave a steering mechanism (such as moveable guide wheel, directionalmagnets, asymmetric brakes, or the like) that allows carrier 430 to makea right turn onto segment G at decision point 402, without theassistance of an external gate integrated into the track. In theseembodiments, carrier 430 engages the steering mechanism at decisionpoint 402 to make the turn onto segment G.

Carrier 430 can determine its rough location—its current track section,such as section J, by reading encoding in the track, such as opticalencoding, or RFID tags. In some embodiments, carrier 430 uses multiplemeans to determine its location within the track system 400. Forexample, RFID tags can be used to determine generally on which tracksegment the carrier 430 is located, while optical encoding or otherprecise encoding can be used to determine the position within that tracksegment. This encoding can also be used to determine velocity,acceleration, or jerk by observing changes in the encoding (e.g.,derivatives from the position information).

Carrier 430 can use the identification of the current track section todetermine the appropriate route to the destination section either byexplicit instruction received by the central management processor 440 orby looking up an appropriate route in an onboard database in memory 304,as shown in the onboard control systems in FIG. 5. In some embodiments,the carrier 430 has an understanding of how to reach section G fromsection J based on a map stored in the memory of carrier 430 in memory304. This map can include a simple lookup table or a tree of tracksections where each node is linked by the corresponding decision points,or vice versa. For example, upon identifying that the carrier iscurrently in the track section J, the onboard database can informcarrier 430 to proceed to decision point 402 to be switched to the rightonto section G.

As shown in FIG. 6, carrier 430 responds to instructions for Route 1 byproceeding onto section G and stopping at a position near pipette 420.Once the carrier 430 is stopped, it can receive additional instructionsfrom the analyzer/testing station controlling pipette 420. For example,analyzer 205A can control pipette 420 and can instruct carriers onsection G to position themselves at precise points along section G. Thisallows analyzer/testing stations to treat track sections as randomaccess queues. For example, once carrier 430 stops on section G,additional instructions can be conveyed via central management processor440 or directly from analyzer 205A to the carrier 430 via RFtransmission or other means, such as local optical or inductive/nearfield signals. These instructions can include halting while anothercarrier interacts with pipette 420, and subsequently proceeding to aposition accessible to pipette 420, when analyzer 205A is ready toperform one or more assays on the sample carried by carrier 430.

Once analyzer/testing station 205A has finished interacting with thesample carried by carrier 430, additional routing instructions can besent to the carrier 430 from the central management processor 440. Forexample, Route 2 can include routing instructions to proceed to sectionH to interact with pipette 422. In some embodiments, the routing tablescontained within onboard memory 304 of carrier 430 have sufficientinformation about the track layout to allow the carrier to route itselfto section H. In other embodiments, a list of routing steps can betransmitted to carrier 430 via central management processor 440. It willbe appreciated that other embodiments can include conveying any subsetof the route to carrier 430 and/or sending routing instructions in apiecemeal fashion, such that carrier 430 always knows the next routingstep, and optionally subsequent routing steps.

In this example, carrier 430 receives a route list representing Route 2from central management processor 440 instructing it to proceed viasection G to decision point 412. At decision point 412, carrier 430 willinitiate switching onto section A by interacting with a gate or byturning as described above. Carrier 430 can take into account curvedtrack conditions on section G and section A to ensure that accelerationand jerk conditions do not exceed a threshold requirement for the sampleit carries. This can prevent spillage or instability during transit. Theroute information received by carrier 430 then instructs carrier 430 toproceed through decision point 402 without turning. The trajectory usedin Route 2 when approaching decision point 402 can be different (e.g.,faster) from that used during Route 1, because carrier 430 knows that itdoes not need to make a sharp right turn onto section G. In someembodiments, this allows carrier 430 to approach decision point 402 witha substantially greater velocity during Route 2 than during Route 1. Bytraversing decision point 402 faster if carrier 430 is not turning,carrier 430 can complete Route 2 in less time than embodiments in whichcarrier 430 must slow down for possible switching at each decisionpoint. This is an improvement over the prior art, where carriers aretypically halted and singulated, regardless of whether the carrier isturning or not.

After passing decision point 402, carrier 430 proceeds onto section B.At decision point 404, carrier 430 proceeds to section C. At decisionpoint 406, carrier 430 prepares and turns onto section I, where it stopsfor interaction with pipette 424. Like section G, section I can act as aqueue for pipette 424 and carrier 430 can be controlled under localinstruction by the analyzer/testing station 205B served by section I.

When pipette 424 is done interacting with carrier 430, centralmanagement processor 440 can provide new routing instructions to carrier430 instructing carrier 430 to proceed onto an output path K. Route 3can be handled in the same manner as Route 1 and Route 2. Upon receivinginstructions for Route 3, carrier 430 proceeds down section I todecision point 408 where it turns back onto a main track section E andproceeds past decision point 410, track section F, and decision point412 (without needing to slow down in some embodiments), and onto sectionK where the carrier 430 and/or the sample can be removed from the systemby an operator. Carrier 430 can then be reused for samples at inputsection J. Upon receiving instructions for Route 4, carrier 430 proceedsdown section D to sample handling station 205C and to decision point408, where it turns back onto a main track section E and then proceedsthe same as Route 3.

In some embodiments, each track section of FIG. 6 can be configured toinclude one or more speed zones. This may be represented as a speed oracceleration limit in software that maintains motion profiles for eachcarrier. For example, section D may be represented for trajectorycontrol as a slow speed zone for all carriers to account for theinherent centripetal forces exerted by the track as carriers traversesection D. Similarly, track sections can include multiple speed zoneswithin the track section, which may include motion profile rules. Forexample, a carrier may slow down responsive to software enforcement ofrules that identify the latter portion of section C as a braking zonedue to the upcoming speed limited zone in track section D. In someembodiments, software responsible for maintaining motion profile rulesfor carriers may take into account an upcoming speed zone and brake inan unlimited track section in anticipation. Furthermore, different tracksection portions can be represented as dynamic speed zones. For example,a stopping point for interaction with a pipette can be represented as aspeed zone with a speed of zero for carriers that should stop at thatlocation. This may allow trajectory enforcing software to automaticallyslow down the affected carrier as it approaches the stopping position.

FIG. 7 shows a general operational diagram of carrier 430 as it followsrouting instructions. As can be seen in method 500, the actions can betaken by the carrier with minimal control by, or interaction with, acentral scheduler, such as a central management controller. At step 501the carrier receives routing instructions from, for example, a centralscheduler. In this example, the routing instructions include enoughinformation for the carrier to determine its entire route to adestination point in the track system. These instructions can include alist of all routing points, including decision points to turn at andsections to traverse. In some embodiments, routing instructions caninclude the destination point and onboard routing information can beused by the carrier to determine the best route to take. It will beappreciated that, when at least a main track is unidirectional, therouting calculation by the carrier is fairly simple and can comprise anyknown method including searching a tree of nodes and sections orsearching a lookup table of possible route permutations.

These instructions can also include velocity and acceleration motionprofiles for each section. In some embodiments, velocity andacceleration for each section of track can be calculated by the carrierbased on its payload and based on information in an onboard database,such as length of track, curvature of track, location of decisionpoints, the type of sample or payload being carried, and considerationof whether the carrier will turn or proceed in the same direction uponreaching a decision point. In some embodiments, the routing informationreceived at step 501 also includes timing information to instruct thecarrier when to begin transit and/or when to complete transit.

Upon receiving routing instructions and beginning transit, the carrierdetermines its current location and optionally the direction needed tobegin its route at step 502. In a general sense, a carrier can only movein two directions, forward or backwards and, in some embodiments,initiate a turn while moving. Because of the simplified movement model,a carrier can begin its transit even if it only has a roughunderstanding of its current location, such as by acquiring the currenttrack section by RFID information. In some embodiments, the carrier usesmore precise encoding in the track to determine its current locationwithin a track section before proceeding.

Once the current position and necessary direction is determined, thecarrier can begin transit at step 504. By using an understanding of thelocation on the track, geometry of the current track, distance to thenext decision point, type of sample/payload, and current velocity, thecarrier can determine a safe acceleration profile to begin transit. Forexample, if a carrier is a large distance away from the next decisionpoint and is currently stopped, the carrier can begin accelerating at amaximum acceleration for the sample. In some embodiments, theacceleration of the carrier is ramped up to avoid exposing the sample toa high degree jerk.

FIG. 8 shows an exemplary acceleration motion profile that can be usedto limit jerk and acceleration, while minimizing transit time. By usinga trapezoidal acceleration profile, acceleration is ramped up to avoidunnecessary jerk until acceleration reaches a safe amount that is lessthan a threshold amount to avoid damaging or spilling the sample. Byensuring that acceleration is less than a threshold amount, a carriermay have some acceleration available to mitigate collisions or handleother unexpected situations without exceeding an acceleration thresholdfor the payload. Generally, maximum velocity will be reached midwaybetween a start point and a stop point. In some embodiments, there is notop speed for a straight section of track, but curved sections of trackare governed by a top speed to prevent excessive lateral acceleration.These speed limits and acceleration thresholds may be known to anintelligent carrier, and may be accessible in onboard memory. The exactmotion profile used by a carrier can vary depending on the payload beingcarried. For example, empty carriers or carriers transporting reagentsor non-sample payloads may utilize a motion profile that has higherlimits than a motion profile that carries a sample.

Unlike traditional friction tracks, which are governed by a fixedvelocity of the track, some embodiments of the present invention canenable dynamic acceleration profiles and allow carriers to move at muchgreater average velocity than the prior art. In some embodiments, it isgenerally desirable to limit the maximum transit time between any pointswithin the track system to less than a portion of an operation cycle ofthe clinical analyzer. For example, if the maximum distance between anypoints on a track system is 25 m and the operation cycle time is 20seconds, it may be desirable to ensure that the average velocity of thecarrier, including all turns, acceleration, deceleration, starting, andstopping, is sufficient to traverse 30 m in 5 seconds or less, or 6 m/s(˜2.1 km/hr). Because a majority of the time in transit is spentaccelerating or decelerating, it will be appreciated that the maximumvelocity of the carrier on a straightaway can be substantially higherthan this average velocity.

Because jerk and acceleration should be limited for samples, real-timecontrol of acceleration is desired. This goal is furthered by givingcontrol of acceleration to the carrier itself so that it can monitor itscurrent trajectory using accelerometers or other sensors. The carriercan dynamically change its trajectory based on track conditions such aslocation, traffic, and the need to slow down for an upcoming turn. Inthis manner, the carrier can be responsible for monitoring andcontrolling its own dynamic stability conditions.

Referring back to FIG. 7, at step 510, the carrier determines whether ornot it is safe to continue accelerating or decelerating in accordancewith the trajectory determined in step 504. Step 510 can includecollision detection or checking for other unexpected obstructions or asystem-wide or carrier-specific halt command. In some embodiments, thedecision at step 510 is based on collision detection sensors, includingRF rangefinders, but can also include status information about the trackreceived from the central management controller or from other carriersat step 505. This status information can include, for example, positionand trajectory information about surrounding carriers or updatedcommands such as a halt instruction or new route instructions.

If the carrier determines at step 510 that it is not safe to continuewith the planned trajectory, the carrier can take steps to mitigate oravoid a collision at step 512. For example, if it is determined that theacceleration profile will place the carrier dangerously close to anothercarrier, the carrier can begin slowing down. In some embodiments, thedecision to slow down to avoid collision is based on an extrapolation ofthe current trajectory and the observed trajectory of the other carrier.If it is determined that the current trajectory will cause the carrierto come within an unsafe following distance from the carrier ahead ofit, the mitigation procedure will be initiated. In some embodiments,each carrier is modeled as having a collision zone into which it isunsafe to enter. This collision zone moves with the carrier. If acarrier senses that it will invade a collision zone of another carrier(or another carrier will invade the instant carrier's collision zone),the carrier can mitigate the collision by decelerating (or acceleratingto avoid a rear end collision in some embodiments).

After the carrier decelerates/accelerates to mitigate a collision, thecarrier proceeds back to step 504 to determine an updated trajectorythat takes into account the new collision avoidance conditions. If nounsafe condition is detected, the carrier proceeds with implementing itstrajectory at step 514 (e.g., proceed with a portion of the trajectorybefore repeating steps 504-510 to allow for continuous monitoring ofconditions). This can include accelerating or decelerating and observingtrack encoding and accelerometer information to determine its currentstatus and trajectory. In some embodiments, the carrier will communicateits current status, including location, trajectory, and/or plannedtrajectory to the central controller and/or other carriers to assist inrouting and collision avoidance at step 515.

As the carrier begins iteratively implementing its planned trajectory,it observes the track for upcoming landmarks, such as its terminaldestination or an upcoming decision point at step 520. These landmarkscan be identified via important features in the track, such as a warningor braking LED, by extrapolating the distance to a landmark from theobserved encoding, or by some combination thereof. If no landmark isupcoming, the carrier continues to step 504 and continues iterativelycalculating and implementing a planned trajectory.

In this example, there are two types of important landmarks. The firstlandmark is the destination of the carrier. The carrier can determine ifit is nearing its destination based on track encoding or a landmarkfeature such as an LED and uses information to begin stopping orcomplete a stopping procedure at step 522. For example, a carrier may beinstructed to stop at a precise location accessible to a pipette. Thisprecise location may include an LED in the wall or floor of the track toassist a carrier in the stopping at a precise location with millimeteraccuracy. In some embodiments, the calculated trajectory at step 504 isused to get a carrier in a rough location of its destination, while astopping procedure at step 522 is used to determine the precise stoppedlocation, such as by searching for a nearby LED landmark and stopping atthe appropriate position.

Another important landmark is a decision point. Encoding or warning LEDsin the track can convey the position of an upcoming decision point to acarrier. For example, a central management controller may illuminate anLED at a braking position on the track some distance before a decisionpoint to alert the carrier to decelerate to prevent unnecessaryacceleration or collision at decision point. In other embodiments, thecarrier extrapolates the relative position of an upcoming decision pointfrom the track encoding and uses this distance to update its trajectory,if necessary, at step 524. At step 524, a carrier determines therelative location of a decision point and determines, based on itsrouting information, if the carrier will be turning or proceeding at thedecision point. If the carrier will be turning, it may be necessary toupdate the trajectory to begin decelerating so that the velocity of thecarrier is slow enough when it turns at the decision point to preventunnecessary lateral forces that could harm or spill a sample.

In many instances, the carrier will be proceeding past the decisionpoint without turning. In these instances, it may not be necessary toupdate the trajectory and the carrier can continue at its currentvelocity or even continue to accelerate through the decision point.

If the carrier determines that it needs to turn at the upcoming decisionpoint, the carrier can slow down and initiate the turn at step 526. Insome embodiments, the carrier is only capable of forward or backwardsmovement without assistance. In these embodiments, the carrier orcentral management controller can communicate with a switching mechanismat the decision point, at step 527, to ensure that any mechanical orelectromagnetic devices in the track system 400 are engaged to directthe carrier in the appropriate direction when it traverses the decisionpoint. Examples of devices in the track can include mechanical switchesthat block one path at a fork and assist the carrier in turning down theother path at the fork (like a railroad switch that can be mounted torails or a gate when the track is shaped like a trough), magnets thatpull the carrier in one direction or another, or changing signaling inthe path that assists the carrier in turning, such as an LED that thecarrier follows or an LCD or e-ink panel in the track that includes aline that can be followed by the carrier if the carrier is equipped withtraditional line-following capabilities. Unlike prior art configurationsthat singulate, scan, and push individual carriers after they stop at adecision point, some embodiments of the present invention can negotiatea turn before a carrier physically arrives at a decision point. This canallow a carrier to proceed at a velocity limited by the curvature of aturn, rather than having to stop or wait for other mechanisms in orderto turn.

In embodiments where a carrier has some steering capability and can turnat a decision point without the assistance of the next internal switch,the carrier can engage its steering mechanism to direct it to theappropriate path upon approaching the decision point. After turning atthe decision point (or proceeding without turning) a carrier returns tostep 504 to determine its next trajectory.

Embodiments of the present invention may be integrated with existinganalyzers and automation systems. It should be appreciated that carriersmay be configured in many shapes and sizes, including layouts andphysical configurations suitable for use with any contemplated analyzeror instrument. For example, in some embodiments, a carrier may includemultiple slots for carrying multiple samples around an automation track.One embodiment, for example, may include a physical layout of atube-holding portion of a carrier with multiple slots in one or moretransport racks. Each rack may include multiple slots (e.g., five ormore slots), each slot configured to hold a tube (e.g., a sample tube).

Although the invention has been described with reference to exemplaryembodiments, it is not limited thereto. Those skilled in the art willappreciate that numerous changes and modifications may be made to thepreferred embodiments of the invention and that such changes andmodifications may be made without departing from the true spirit of theinvention. It is therefore intended that the appended claims beconstrued to cover all such equivalent variations as fall within thetrue spirit and scope of the invention.

What is claimed is:
 1. An automation system for use in in vitrodiagnostics comprising: a track configured to provide one or more pathsbetween a plurality of testing stations; a plurality of carriers, eachcomprising an onboard processor configured to make local trajectorydecisions; and at least one central controller configured to assigndestinations to the plurality of carriers and convey routinginstructions to the plurality of carriers, which includes anidentification of at least one track section to traverse, wherein eachcarrier is configured to hold one or more fluid samples and move the oneor more fluid samples to one of the plurality of testing stations inresponse to receiving the routing instructions.
 2. The automation systemof claim 1, wherein each carrier is configured to monitor and limitacceleration to a threshold that depends on the fluid sample beingcarried.
 3. The automation system of claim 1, wherein each carrier isconfigured to monitor and limit jerk to a threshold that depends on thefluid sample being carried.
 4. The automation system of claim 1, whereineach carrier is configured to observe landmarks in the track todetermine its current location.
 5. The automation system of claim 1,wherein each carrier is configured to observe landmarks in the track todetermine its current location relative to a decision point.
 6. Theautomation system of claim 1, wherein the track includes a plurality ofdecision points that allow a carrier to be routed between multiplesections within the track and each carrier is configured to make arouting determination for each decision point it encounters.
 7. Theautomation system of claim 6, wherein each carrier is further configuredto make the routing determination without coming to a stop.
 8. A carrierfor transporting fluid containers in an in vitro diagnostics environmentcomprising: a processor configured to navigate the carrier between aplurality of points in a track; and a communications system configuredto receive a first set of routing instructions, including at least onedestination testing station, wherein the processor is further configuredto direct the carrier to the at least one destination testing stationautonomously upon receipt of the first set of routing instructions. 9.The carrier of claim 8, further comprising one or more sensorsconfigured to detect a collision condition with one or more othercarriers.
 10. The carrier of claim 8, wherein the processor isconfigured to monitor and limit acceleration to a threshold that dependson the fluid container being carried.
 11. The carrier of claim 8,wherein the processor is configured to monitor and limit jerk to athreshold that depends on the fluid sample being carried.
 12. Thecarrier of claim 8, wherein the carrier is configured to observelandmarks in the track to determine its current location.
 13. Thecarrier of claim 8, wherein the track includes a plurality of decisionpoints that allow a carrier to be routed between multiple sectionswithin the track and the carrier is configured to make a routingdetermination for each decision point it encounters.
 14. The carrier ofclaim 13, wherein the processor is further configured to make therouting determination without coming to a stop.
 15. An automation systemfor use in in vitro diagnostics comprising: a plurality of stations,including at least one testing station; a track configured to provideone or more paths between the plurality of stations; and a plurality ofcarriers, each configured to carry one or more fluid containers andtraverse the track between the plurality of stations, wherein theplurality of carriers move independently in accordance with a predefinedmotion profile.
 16. The automation system of claim 15, wherein each ofthe plurality of carriers comprises an onboard processor.
 17. Theautomation system of claim 15, wherein each of the plurality of carriersis configured to monitor and limit acceleration to a threshold thatdepends on a fluid sample being carried.
 18. The automation system ofclaim 15, wherein each of the plurality of carriers is configured tomonitor and limit jerk to a threshold that depends on a fluid samplebeing carried.
 19. The automation system of claim 15, wherein the trackincludes a plurality of decision points that allow each of the pluralityof carriers to be routed between multiple sections within the track andeach carrier is configured to make a routing determination for eachdecision point it encounters.
 20. The automation system of claim 19,wherein each of the plurality of carriers is further configured to makethe routing determination without coming to a stop.